The Ancient Volcanoes of Great Britain, Volume 1 (of 2)Note 157 — Chapter XII · CHARACTERS OF THE SILURIAN SYSTEM IN BRITAIN. THE ARENIG VOLCANOESReading editionQuart. Journ. Geol. Soc. vol. xlv. (1889), p. 432.◇Copy noteReturn to CHAPTER XII CHARACTERS OF THE SILURIAN SYSTEM IN BRITAIN. THE ARENIG VOLCANOES